Letterhead of Dendreon Corporation]

Exhibit 10.15

[Letterhead of Dendreon Corporation]

June 22, 2004

VIA U.S. POSTAL SERVICE

X. Xxxxx Xxxxxxxxxx, M.D.

Corus Pharma, Inc.

0000 Xxxxx Xxxxxx, Xxxxx 000

Seattle, WA 98121

Re: Sublease at 0000 Xxxxx Xxxxxx

Dear Xx. Xxxxxxxxxx:

This letter confirms the following agreement between Dendreon Corporation (“Dendreon”) and Corus Pharma, Inc. (“Corus”) under the Sublease dated September 6, 2002, as amended (“Sublease”). Effective March 1, 2004, Xxxxx relinquished and Xxxxxxxx regained Office 345, Office 344, and Open Lab Area 333A for a total of 889 square feet. Therefore, as of March 1, 2004, the Base Rent due by Corus under the Sublease is reduced by $2, 560 per month. Except as set forth expressly in the preceding two sentences, all of the terms and conditions of the Sublease between Dendreon and Corus remain in full force and effect.

Please signify your agreement with the foregoing by signing the acknowledgement line below and returning the original of this letter to me. If you have any questions, or if this letter does not accurately reflect our agreement, please call Xxxxxxx Xxxxxx, Vice President Legal Affairs at (000) 000-0000.

Very truly yours,

/s/ Xxxxxxx X. Xxxxxx

Xxxxxxx X. Xxxxxx

Vice President, Legal Affairs

						ACKNOWLEDGED AND AGREED: Corus Pharma, Inc.
cc:    Xxxx Xxxxxxx
						By:		/s/ X. Xxxxx Xxxxxxxxxx
						Title:		CEO
						Date:		6/28/04